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Description

The following analytic detects attempts to exploit the CVE-2023-42793 vulnerability in JetBrains TeamCity On-Premises. It identifies suspicious POST requests to /app/rest/users/id:1/tokens/RPC2, leveraging the Web datamodel to monitor specific URL patterns and HTTP methods. This activity is significant as it may indicate an unauthenticated attacker attempting to gain administrative access via Remote Code Execution (RCE). If confirmed malicious, this could allow the attacker to execute arbitrary code, potentially compromising the entire TeamCity environment and leading to further unauthorized access and data breaches.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Web
  • Last Updated: 2024-05-23
  • Author: Michael Haag, Splunk
  • ID: 89a58e5f-1365-4793-b45c-770abbb32b6c

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1190 Exploit Public-Facing Application Initial Access
Kill Chain Phase
  • Delivery
NIST
  • DE.CM
CIS20
  • CIS 13
CVE 


1
2
3
4
5
6



| tstats count min(_time) as firstTime max(_time) as lastTime from datamodel=Web where Web.url IN ("/app/rest/users/id:1/tokens/RPC2*") Web.status=200 Web.http_method=POST by Web.http_user_agent, Web.status Web.http_method, Web.url, Web.url_length, Web.src, Web.dest, sourcetype 
| `drop_dm_object_name("Web")` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `jetbrains_teamcity_rce_attempt_filter`

Macros

The SPL above uses the following Macros:

:information_source: jetbrains_teamcity_rce_attempt_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • Web.http_user_agent
  • Web.status
  • Web.http_method
  • Web.url
  • Web.url_length
  • Web.src
  • Web.dest

How To Implement

The following analytic requires the Web datamodel. Ensure data source is mapped correctly or modify and tune for your data source.

Known False Positives

If TeamCity is not in use, this analytic will not return results. Monitor and tune for your environment.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
81.0 90 90 Potential JetBrains TeamCity RCE Attempt detected against URL $url$ on $dest$.

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 2